Will Pacific walrus be next species protected due to shrinking sea ice?

Recently, a federal appeals court ruling determined that polar bears, those poster children of the effects of climate change, could keep their "threatened" status as listed under the Endangered Species Act, despite objections from the state of Alaska and other entities. Now, the Pacific walrus -- another species that calls Alaska home -- may become another animal to be listed on the basis of climate change's negative effect on its summer sea ice habitat.

Another recent court ruling said that a determination can now be made on whether or not to include a backlog of more than 260 species for the endangered species list. The U.S. Fish and Wildlife Service has been tasked with making a determination on each of those species by 2018.

The FWS released a timeline of when each species might be addressed. Included in that list are three Alaska species:

? Kittlitz's murrelet, a "small, chubby seabird" that's "probably the least well known of any bird in America" and whose range stretches from Alaska's Southeast Panhandle to Russia. Its listing will be determined before the end of the 2013 fiscal year, in September.

? The yellow-billed loon is due to be addressed in FY 2014. A relative of the common loon with an ivory-colored or yellow bill, the birds call lakes on Alaska's Arctic tundra home in the summertime.

? The Pacific walrus is due to have its status reviewed in 2017. A resident of the Chukchi Sea in the summertime and the Bering Sea Coast in the winter, the walrus is heavily dependent upon sea ice activity for its habitat, hanging out on the ice in the fruitful waters above the continental shelf to forage for food.

The walrus was originally listed as a candidate for protection under the ESA in 2011, when a yearlong review by the FWS found that the walrus may merit eventual ESA safeguards.

"After review of all the available scientific and commercial information, we find that listing the Pacific walrus as endangered or threatened is warranted," the agency wrote. "Currently, however, listing the Pacific walrus is precluded by higher priority actions to amend the Lists of Endangered and Threatened Wildlife and Plants."

A big part of the recommendation came as a result of receding levels of summertime Arctic sea ice, widely attributed to warming temperatures related to climate change. 2007 marked a record low for Arctic sea ice extent, a record broken again just last year. In 1980, the U.S. Geological Survey says that Arctic sea ice covered about 7.5 million square kilometers. In 2012, it covered less than 3.5 million square kilometers.

Those low ice extents were also what led to the polar bear's initial listing as threatened under the ESA in 2008, and Pacific walruses may now face the same fate.

Evidence of impact

The impact of receding sea ice on northern walrus populations is already clear: In 2007, thousands of walrus hauled out on shore near the Arctic community of Point Lay, an unprecedented event. It wouldn't be unprecedented for long, though; they didn't return in 2008, but showed up in 2009, 2010 and 2011.

"Last winter (2011-2012) was very cold, and there was a lot of ice development," Oakley said. "There was a huge ice floe that got grounded on Hanna Shoal, and (the walruses) stayed in that region throughout the summer."

She said that it's hard to judge what happens year to year, because it's based on the behavior of the ice and what the walruses decide.

"It's such a dynamic situation, we just don't really know," she said. "It's like, 'what are they going to do this year?' Well, who knows?"

This unusual behavior was a strong enough indicator for the FWS to list the walrus as a candidate for eventual ESA protection, considering how integral sea ice is to the habitat and life cycle of the Pacific walrus. According to Sonja Jahrsdoerfer, FWS endangered species coordinator for Alaska, such a move isn't out of line with a lot of other species Outside of the state. Alaska's large landmass and relatively sparse population has helped hinder the habitat destruction that plagues many of the species to be listed in the rest of the U.S.

"In the Lower 48, many of the listings occur because of loss of habitat." Jahrsdoerfer said. "In Alaska, we still have a lot of functional habitat and ecosystems."

Which helps explain why despite Alaska's huge size and diverse wildlife, only three species made the FWS agenda for ESA evaluation.

But the habitat of the Pacific walrus certainly seems to be under threat, given their behavior in recent years, and scientists are working to further understand that behavior as well as other basic questions about the species. In that regard, the 2017 deadline gives researchers greater opportunity to expand on their knowledge.

"From our perspective as the research scientists, we actually have some time to gather information," Oakley said.

One of the questions in need of answering is just a basic population estimate for Pacific walrus. Oakley said that determining a population has been "...a very, very challenging question to try to answer."

She added that the last population estimate came in 2006, and it had a very wide possible range, essentially a large margin of error around the estimated number. The fact that walrus spend much of their lives underwater makes counting them difficult.

"That remains kind of the holy grail, the windmill that we're all tilting toward, trying to solve that question," Oakley said.

Scientists are evaluating many other aspects of the Pacific walruses behavior and health, including evaluating how hard it is for them to forage from shore versus from the ice, and whether or not that could negatively impact their survival.

With any luck, a lot more information will be available by the time FWS must revisit the potential listing of the species under the ESA. That means that whatever listing the agency determines is appropriate -- if any -- will be rooted in a greater knowledge of a species that many people in Alaska rely upon for subsistence needs.

And in turn, it may help the walrus stick around for a long time to come.